Fusible device



Nov. 29, 1960 w. A. GASKILL 2,962,563

FUSIBLE DEVICE Original Filed Aug. 12, 1955 2 Sheets-Sheet 1 Fig.l.

Nov. 29, 1960 w. GASKILL FUSIBLE DEVICE 2 Sheets-Sheet 2 Original Filed Aug. 12, 1955 llllll-IIL O A .iLTIlT HHI IJHHHHHF .HHHHHH IHH I 1 T n m n a United States Patent FUSIBLE DEVICE William A. Gaskill, Hampton, Ga., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Original application Aug. 12, 1955, Ser. No. 527,977. Dividedand this application Mar. 18, 1958, Ser. No. 722,221

7 Claims. (Cl. 200133) This invention relates to fusible devices in general, and, more particularly, to improved mounting constructions therefor. This application is a division of my copending application filed August 12, 1955, Serial No. 527,977, entitled Fusible Device, now United States Patent 2,892,060, issued June 23, 1959, and assigned to the assignee of the instant application.

A general object of my invention is to provide an improved fusible device which will render a more effective and improved operation than has been obtained heretofore.

A more specific object of my invention is to provide an improved mounting construction for a fuse device which will carry heavy currents therethrough without heating and which will provide improved contact engaging surfaces.

Another object is to provide a simplified mounting construction for a double-barreled type of fusible device.

Another object of the present invention is to provide an improved mounting construction for a double-barreled fuse in which a contact bridging member is secured to the ferrules of the fuse to form rigid support therefor and also to provide good contact bearing surface to insure equal division of the current through the two fuse tubes.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings, in which:

Figure 1 is a front elevational view of a fusible device incorporating the features of my invention, and shown in the closed, operative position;

Fig. 2 is a side elevational view of the fusible device shown in Fig. 1, also indicated in the closed, operative position;

Fig. 3 is a side elevational view of the double-barreled fuse holder, partially broken away in vertical section to disclose internal features of the fuse;

Fig. 4 is a top plan view of the upper or top ferrule assembly for the fusible device of Fig. 3;

Fig. 5 is a side elevational view of the top ferrule assembly shown in Fig. 4;

Fig. 6 is an inverted plan view of the lower ferrule :assembly of the fusible device shown in Fig. 3;

Fig. 7 is a side elevational view of the lower ferrule assembly; and,

. pivotal rotation.

, 2,962,568 Patented Nov. 29, 1960 The double-barreled fuse holder 5 is shown in Fig. 3 in a partially assembled state, a hook-stick operated latch 6 being omitted in the view of Fig. 3. It will be observed that a contact bridging member 7 is brazed to each of the ferrules 8 disposed at the lower end of the fuse tubes 9 and has a trunnion pin 10 and a guide pin 11 rigidly afiixed thereto.

As more clearly shown in Fig. 2 of the drawings, the trunnion pins 10 associated with the two contact bridging members 7 are disposed within slots 12 associated with a hinge member 13 of generally bifurcated construction, which is associated with the lower terminal 14 of the device. As is obvious, by placing the prong of a hook-stick within an eye 15 of the latch 6, one may raise the nose 16 of the latch 6 and unlatch the same from a latching member 17 associated with the upper terminal 18 of the fusible device 4, to effect thereby rotative counterclockwise motion of the double-barreled fuse holder 5 about the trunnion pins 10 as a center. This will permit opening of the connected circuit, as well known.

Such opening rotative motion may continue until the contact bridging members 7 engage stop shoulders 13a integrally formed with the hinge member 13, as shown in Fig. 8. It .will, of course, be apparent that one may also employ the hook-stick to effect removal of the fuse holder 5 completely out of the hinge member 13 by placing the hook-stick within a cradle portion 19 of the latch member 6 with the prong of the switch stick in the slot 6a in a manner more clearly brought out in US. Patent 2,024,744, issued December 17, 1935, to Herbert L. Rawlins, and also assigned to the assignee of the instant application. Since this feature is not a part of the present invention, a further description thereof appears unnecessary, and reference may be had to the aforesaid Patent 2,024,744 for details of such a disassembly operation.

A contact and bridging member 20 is associated with each side of the ferrules 21 disposed at the upper end of the fuse holder 5, preferably being brazed thereto. It will be observed, with particular reference to Figs. 1 and 2, that fuse clip fingers 22, 23, associated respectively with the upper terminal 18 and the lower terminal 14, bear laterally against the side terminal surface faces of the contact bridging members 7, 20. The side terminal surface portions 7a, 20a, are disposed inwardly from the ends of the fuse holder 5 comprising the two fuse tubes 9. In the closed-circuit position of the device, as shown in Fig. 1, the fuse clip terminals 22, 23 straddle the inner fuse tube 9 in contacting the side terminal surfaces of the contact bridging members 7, 20. Thus, the bridging members 7, 20 not only serve to effect rigid positioning of the fuse tubes 9 with respect to each other, but also the bridging members 7, 20 electrically connect the two fuse tubes 9 in electrical parallel, and moreover serve as the side contact bearing portion with the fuse clip fingers 22, 23. In addition, the lateral edges of the contact bridging members 7 engage the stop shoulders 13a as shown in Fig. 8. There is thus provided a considerable simplification in the disclosed mounting construction, involving relatively few parts with the contact engagement being maintained by the flexibility which is inherent in the fuse clips 22, 23.

Figs. 4 and 5 collectively show in detail the upper ferrule assembly 24 and the manner in which the contact bridging portions 20 are secured to the ferrules 21. A clevis 25 is aflixed to the outermost ferrule 21, as shown, to which is pivotally mounted the latch 6 by means of a pivot pin 26.

Figs. 6 and 7 collectively show more clearly in detail the lower ferrule assembly 27 comprising the ferrules 8 and the two bridging members 7, which support the trunnion pins 10 and the guide pins 11, the latter moving under the terminal fuse clips 23 during the closing operation to prevent the operator from lifting the fuse holder upwardly. This mounting construction is strong and rigidly supports the ferrules 3, 21 in fixed position with the contact bridging members 7, 20 protruding laterally sufiiciently to provide contact surfaces engaging the fuse clip fingers 22, 23 and with the contact bridging members '7 engaging the stop shoulders 13a in the open-circuit posinon.

The ferrule assemblies 24, 27 are secured to the fuse tubes 9, which are preferably formed from Pyrex glass tubing, by an epoxy resin with an inert filler. ThiS avoids the use of any fuse fittings or mounting clamps, which would not be suitablein the case of using glass tubing for the fuse tubes 9.

The interrupter assembly 28, including the fusible wires 33 extending between the ferrules 8 and 21, more clearly shown in Fig. 3 of the drawings, is described in detail in the aforesaid Patent 2,892,060 and will not here be described. i

From the foregoing description of my invention, it will be apparent that l have provided an improved fusible device, in this particular instance adapted for service at 2,500 and 5,000 volts. The fuse is completely inorganic and was developed specifically for 400 ampere motorstarting servi e but, of course, is not limited to these current and voltage ratings. i v

From the foregoing description, it will be apparent that I have provided a completely inorganic 400 ampere, 5 kv. fuse, which will interrupt over the entire range of current from minimum melting to 60,000 amperes, and is particularly suitable for application in explosive and corrosive atmospheres.

Also, it will be apparent that I have provided an improved, sturdy, simplified, and low'cost mounting construction, which provides excellent current-carrying surfaces With the fuse clips 22, 23 and brings about an equal division of current through the two fuse tubes 9.

Although I have shown and described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

claim as my invention:

l. A double-barreled fusible device including a fuseclip terminal having a pair of spaced cooperating contact fingers, a double-barreled fuse holder including a pair of substantially parallel fuse tubes, said fuse tubes having a pair of adjacently disposed conducting ferrules at one end thereof, a contact bridging member fixedly conductively secured to the sides of said fuse-tube ferrules, said contact bridging member having a side terminal surface partion extending laterally outwardly a greater distance than the sides of the fuse-tube ferrules so as to make sole contacting engagement with one contact finger of said fuse-clip terminal to the exclusion of the adjacent sides of said fuse-tube ferrules in the closed circuit position of the device, said side terminal surface portion being disposed inwardly from the ends of the fuse-tube ferrules, and the contact fingers straddling one of the fuse tubes in the closed contacting position of the device.

-2. A double-barreled fusible device including a fuseclip terminal having a pair of spaced cooperating contact fingers, a double-barreled fuse holder including a pair of substantially parallel fuse tubes, said fuse tubes having a pair of adjacently disposed conducting ferrules at one end thereof, a pair of contact bridging members fixedly conductively secured to the sides of said fuse-tube ferrules,

said contact bridging members having side terminal surface portions extending laterally outwardly a greater distance in opposite directions than the sides of the fusetube ferrules so as to make sole contacting engagement with said contact fingers of said fuse-clip terminal to the exclusion of the adjacent sides of said fuse-tube ferrules in the closed circuit position of the device, said side terminal surface portions being disposed inwardly from the ends of the fuse-tube ferrules, and the contact fingers straddling one of the fuse tubes in the closed position of the device.

3. A double-barreled fuse assembly including a pair of relatively stationary, spaced, fuse-clip terminals, a doublebarreled fuse holder including a pair of substantially parallel fuse tubes, each fuse tube having conducting ferrules at the opposite ends thereof, a pair of contact bridging members fixedly conductively secured to the outer sides of the ferrules of the pair of fuse tubes at each end thereof, the two pairs of contact bridging members having side contact bearing portions which extend laterally a greater distance than the side surfaces of the fuse-tube ferrules, said side contact bearing portions positioned inwardly from the opposite ends of the fuse tubes, and the outer side contact bearing portions of each pair of contact bridging members making side contacting engagement with a fuse clip terminal in the closed circuit position of the fuse assembly.

4. The combination in a pivotally mounted doublebarreled fuse assembly of a pair of spaced terminal fuse clips, a hinge associated with one of the terminal fuse clips, a pair of adjoining fuse holders adapted for swinging movement about said hinge and having a pair of exposed ferrules at the relatively stationary ends of the fuse holders, a contact bridging member fixedly conductively secured to said exposed ferrules and having a side terminal surface portion engageable with said one terminal fuse clip to the exclusion of the sides of the adjacent ferrules, said side terminal surface portion disposed inwardly from the ends of the fuse holders, said one terminal fuse clip stradding one of said fuse holders in the closed position of the device and cooperative hinge means mounted upon said contact bridging member and rcmovably engageable with said hinge.

5. The combination in a pivotally mounted doublebarreled fuse assembly of a pair of spaced terminal fuse clips, a hinge associated with one of the terminal fuse clips, 21 pair of adjoining fuse holders adapted for swinging movement about said hinge and having a pair of exposed ferrules at the relatively stationary ends of the fuse holders, a contact bridging member fixedly conductively secured to said exposed ferrules and having a side terminal surface portion engageable with said one terminal fuse clip to the exclusion of the sides of the adjacent ferrules, said side terminal surface portion disposed inwardly from the ends of the pair of fuse holders, cooperative hinge means mounted upon said contact bridging member and removably engageable wtih said hinge, and the contact bridging member engaging a stop portion of the hinge to limit motion of the same during the opening operation.

6. A double-barreled fuse assembly including a pair of spaced fuse clip terminals, a pair of spaced tubular fuse holders having tubular exposed ferrules at their opposite spaced ends, a pair of contact bridging members disposed at each end of the double-barreled fuse having side terminal surface portions extending laterally therefrom a greater distance than the sides of the exposed ferrules so that said contact bridging members make sole side contact with said fuse clip terminals in the closed position of the fuse assembly, the fuse-clip terminals straddling one of the tubular fuse holders in the closed-circuit position of the assembly, and one pair of contact bridging members having trunnion pins projecting outwardly for rotatable movement of the double-barreled fuse.

7. The combination in a pivotally mounted doublebarreled fuse assembly of a pair of spaced terminal fuse cl ps, a hinge associated with one of the terminal fuse clips, 21 pair of adjoining fuse holders adapted for swinging 2,962,568 5 6 movement about said hinge and having a pair of ex- References Cited in the file of this patent posed ferrules at the relatively stationary ends of the fuse holders, a contact bridging member fixedly conductively UNITED STATES PATENTS secured to said exposed ferrules and having a side ter- 546,957 Gartner Sept. 24, 1895 minal surface portion solely engageable with said one 5 2,024,744 Rawlins Dec. 17, 1935 terminal fuse clip to the exclusion of the sides of the 2,259,142 Schuck Oct. 14, 1951 adjacent ferrules, said side terminal surface portion 2,662,140 Kozacka Dec. 8, 1953 spaced inwardly from the ends of the fuse holders, and a 2,670,418 Kozacka Feb. 23, 1954 trunnion pin mounted upon said contact bridging mem- 2,713,098 Swain July 12, 1955 her and removably engageable with said hinge. 10 2,879,354 Fahnoe Mar. 24, 1959 

